After your baby swallows milk, it glides past the back of the throat into a muscular tube (the esophagus) and, from there, into the stomach. At the junction of the esophagus and the stomach is a ring of muscles (lower esophageal sphincter) that opens to let the milk drop into the stomach and then tightens to prevent the milk (and the stomach contents) from moving back up into the esophagus. If the stomach contents should happen to re-enter the esophagus, this is called "reflux," which could cause the baby to spit up or vomit.
Why are infants especially prone to reflux?
Every baby spits up or vomits occasionally, and some do quite often or even with every feeding. If, despite the spitting, your baby is content, in no discomfort, growing and experiencing no breathing problems from the vomiting, she is what pediatricians call "a happy spitter" and no treatment is needed. Typically, the lower esophagus valve tightens up sometime in the first year, usually around 4-5 months of age, at which time the spitting up may go away.
What can you do to help your "spitter"?
Sometimes these simple maneuvers help enough to keep your baby as a happy spitter. But when they don't work, your pediatrician may suggest antacid drugs and/or medications that tighten the valve. Each has potential benefits and side effects, and only your pediatrician can decide which, if any, is right for your baby.
If your baby is a spitter and experiencing discomfort, poor growth, choking, gagging, coughing, or frequent respiratory symptoms, then gastro-esophageal reflux disorder (GERD) may be considered by the physician.
However, most babies who have reflux are happy spitters. Medications in such cases should be avoided!